Joint cutting machines



Feb. I24, 1970;

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Lvc=7b`l2 l- Hemnn 17.' Jnner Mwmm United States Patent OM 3,497,261 JOINT CUTTING MACHINES Hermann Josef Schares, 36 Hauptstrasse, Wolsfeld, Germany Filed Mar. 7, 1968, Ser. No. 711,390 Int. Cl. E01c 11/06 U.S. Cl. 299-37 3 Claims ABSTRACT F THE DISCLOSURE The specification describes a machine with vibratory knives for cutting joints in concrete or the like.

The present invention relates to joint cutting machines and more particularly to vibratory joint cutting machines for producing joints in concrete roads or similar purposes in civil engineering, employing a joint cutting knife, a vibrating means for driving the knife, means for adjusting the height of the knife, and a frame which is preferably arranged to travel.

Such machines can be used in the laying of concrete roads to make expansion joints since the making of the joints by laying resilient material partitions before the concrete is laid hinders the operati-on of the concrete laying equipment.

In order to be able to use such joint cutting machines for cutting joints with different dimensions, that is to say different depths and widths and also, in some. cases lengths, the knife of known joint cutting machines is arranged in or on the frame vof the machine in such a manner that it can be removed and exchanged for another joint cutting knife which has the dimensions required for a particular purpose. The operations necessary for such exchange of knives are however tedious to perform and consume a substantial amount of time so that the services of the machine are not available for some time. In order to avoid this, it is possible to use several joint cutting machines equipped with different knives. The disadvantage of this is the high capital cost involved and the loss of time in maneuvering the different machines in and out of position for a change-over in joint dimensions.

One object of the present invention is to provide a joint cutting machine which enables joints with dilferent dimensions to be made in a simple manner without substantially increased capital costs being involved. A further object of the invention is to provide a joint cutting machine which can cut joints of different dimensions without removal and replacement of knives being necessary.

The present invention consists in a vibratory joint making machine for making joints in horizontal slabs, comprising a traveling frame, at least two vertical knives. means for vibrating one of the knives in a vertical direction, means for coupling one of the knives with the vibrating means for causing the knife to vibrate, and means for raising and lowering at least one of the knives.

The vibrating means can be arranged to drive the one knife when it is used and then drive the other knife when it is in use.

The raising and lowering means can be arranged to move each knife.

The machine can comprise a group of three such knives parallel to each other, the outer knives in the group being provided with latching devices for connecting them with the vibrating means selectively.

The outside knives in the group can be carried in their own guide means.

In accordance with a further preferred feature of the invention the latching means include horizontally sliding latches and locking pins for holding them in position. The central knives in the group can have a bottom edge above 3,497,261 Patented Feb. 24, 1970 the bottom edge of the other knives and can be permanently connected with the vibrating means.

With a machine in accordance. with the invention there is the advantage that the different joint cutting knives can be simply and rapidly brought into use using the same vibrating means and the same raising and lowering means'.

With the help of such a joint cutting machine joints on construction sites with different dimensions and forms can be produced in concrete slab more rapidly and more cheaply than hitherto. With the help of the latching means each joint cutting knife can be connected rapidly with the vibrating means, and the tedious removal and exchange of joint cutting knives is not necessary.

One embodiment of the invention is now described with reference to. the accompanying drawing.

FIGURE 1 shows a vibratory joint making machine in accordance with the invention, from the front.

FIGURE 2 shows the machine of FIGURE l from the side.

FIGURE 3 is a section through the machine on the line A-B of FIGURE l to show the latching mechanism.

Referring more particularly to FIGURE 1 of the drawings, it can be seen that the machine in accordance with the invention includes a frame 1 with chassis parts 2 and a raising and lowering mechanism 3 for a joint-cutting knife 4, which together with its vibrating means 5 is detachably connected with the frame 1. At one side, that is to say to the front and rear of the joint-cutting knife 4 there are additional joint-cutting knives 4a and 4b which are carried in suitable guide means allowing vertical movement. The joint-cutting knives 4, 4a, and 4b have different dimensions, that is to say different thicknesses in order to cut corresponding joints. The bottom cutting edge of the central joint knife 4 is higher than the bottoni edges of the knives 4a and 4b. The knives 4a and 4b are held by suitable means, that is to say springs 9, in their upper position.

Using the raising and lowering mechanism 3 it is possilble to raise and lower the joint cutting knife 4, and after operating a connecting mechanism 6 to connect up either one of the additional knives 4a and 4b, as will be further described presently. The latching mechanisms comprise horizontal sliding latches 8 and 8a which are locked by means of vertical pins 7 and 7a. To latch one of the knives 4a and 4b with the vibrating means 5 for operation, the operator raises the pin 7a or 7b and pushes the latch 8 or 8a so that it comes to lie in a position adjacent to the oentral knife 4, this being shown in FIGURE 3 in the case of latch 8a. When the raising and lowering mechanism 3 is operated it therefore not only raises and lowers the knife 4 but also the knife 4b whose latch is in its lefthand position adjacent to the knife 4. Owing to the dilerent levels of the cutting edges of the knives 4 and 4b, the knife 4b can be used, that is to say driven by the vibrating means 5, without it being necessary to disconnect the central knife 4 from the vibrating means. The bottom edge of the knife 4 will still be clear of the concrete or other material in which the joint is to be produced when the knife 4b has penetrated sufficiently to make its full depth of cut and can be retracted by operating the mechanism 3. It is thus possible to make different size joints in concrete or other hardening material using the same machine.

The invention is applicable to machines other than those intended for cutting joints in concrete. For the additional cutting knives it is possible to provide additional vibrating and/or moving devices.

What we claim is:

1. A vibrating joint cutting machinefor making joints in horizontal slabs, comprising a traveling frame, primary and secondary vertical knives mounted for vibratory joint cutting movement, vibratory drive means connected with the primary knife to form a unit, means for raising the unit, and means for coupling the secondary knife with the unit for vibratory actuation of the secondary knife with a lower edge thereof at a lower level than a lower edge of the primary knife.

2. The structure as set forth in claim 1 in which the coupling means comprises horizontally sliding latching means and locking pins.

3. The structure as set forth in claim 1 comprising three knives, the primary knife and two secondary knives, the latter being arranged on each side of the primary knife the coupling means -being adapted for coupling selectively either of the secondary knives with the unit.

References Cited UNITED STATES PATENTS ERNEST R. PURSER, Primary Examiner U.S. Cl. X.R. 

